Exemplary embodiments pertain to the art of gas turbine engines and, more particularly, to an optical probe for gas turbine engines.
Many cases in turbine engines have very restrictive geometry for placing probes to collect Non-Intrusive Stress Measurement System (NSMS) data for vibratory modes on rotating airfoils. Some of the geometries are very thin and also placed between gas paths, as in engines with multiple gas paths. Current probe designs block or obstruct outer gas paths in order to gather data on the inner blades. Not only are the re-operated cases compromised, but the performance of the asset is not indicative of BOM expectations. This is especially important when development engines are tasked with gathering both sets of data (stress and operability) simultaneously.